Apple's delivery and shipping dates on their website have changed for pre-orders for the iPad's April 3rd launch day. What was once shown on Apple's website as 'Delivered On April 3rd' is now 'Ships By April 12th'.
Apple has also removed the ability for people to reserve an iPad for in-store pickup at their retail locations.
By the looks of the Apple Store, all of the inventory expected for the April 3rd launch of the iPad seems to have been spoken for. This could mean they simply sold out of what was expected for early April delivery, or they could possibly be having issues sourcing materials as has been speculated upon over on AppleInsider.
This makes it all that much more important to get your camping gear out for your local Best Buy or Apple Store if you've not made pre-order arrangements yet and are hoping to join the iPad club next Saturday.
Thanks to iPadForums.net member stevegm for pointing this out on the discussion boards!